In view of the wide use of cellulose which is a natural biopolymer having a complex structure and special physical and chemical properties, used for creation during the various historical periods of man activity, of objects of culture, author's right objects, individual creativity articles, various constitutive documents, archive documents of private use and other objects and articles, a very important problem in the archive, antiquarian, criminalistic and judicial activity consists in establishing the correspondence of the claimed date of creation of an article, an object or its fragment to its true (valid) creation date.
At present there are known various methods for determining the age of cellulose-containing materials wherein estimation of respective changes in the physical and chemical properties and the cellulose structure under the environmental effects are determining, said methods being used for estimating the age of the object as a whole object including an object having an image on the surface of the cellulose-containing material which can be made of other materials during the various periods of the life of the cellulose-containing carrier.
Known in the art is a method for determining the age of a carrier made of a based-cellulose material (RO, 116844) which is used for establishing the date of writing of documents, mainly, in determination of the intervention process required for recovery and saving of manuscripts, products of the early period and old books by means of sampling and determination of the level of whiteness in the initial phase and after the heat treatment at 103 . . . 2 degrees centigrade.
Known in the art is a method for determining the age of a fabric made of cellulose (RO, 121151) which is used for the purpose of determining the date of creation of a picture canvas, an article of clothing and old materials by determining the degree of polymerisation of the cellulose using an alkali solution of the Schweizer's reagent.
Known in the art is a method for determining the chemical characteristics of cellulose in samples of paper by the content of carbonyl and carboxyl groups (DE, 102007-44606, B4), wherein there is studied the content of the carbonyl groups decreasing with an increase of the sample age, and the content of the carboxyl groups increasing with an increase of the paper age because of progressive processes of oxidation of the cellulose. The parameters of whiteness and density of the cellulose and paper can be found in the same way.
Known in the art is a method for determining the age of a document written on paper, for example, a manuscript (DE, 3603599, A1), wherein small samples of paper put in a solution for some time and the dissolving can be accelerated by means of ultrasonic treatment. From 5 to 7 solutions are used one after another. The obtained solutions are then subjected to a thin-layer chromatography to determine the disappearance of colour in the solution and evaluated by mathematically finding the numerical value of the gradient of the resultant curve of the exponential function which is used as an index of the document age: a higher curvature of the function corresponds to a younger document, and the smaller one corresponds a more ancient document. However, this method does not allow one to compare the age of paper with the age of the applied colour coating that is required, for example, for determining forgeries and falsification of dates and signatures on the documents.
Known in the art is a method for determining the date of creation of old materials made of cellulose-based fabrics (MID, 3325, F1) including: determination of the degree of polymerisation of the cellulose in an old material by the viscometric method, establishing the level of decomposition of the cellulose in the ratio (%)=100 [2/(GP)i−2/(GP)f], where (GP)f is the degree of polymerisation of the cellulose in the old material, and (GP)i−is the degree of polymerisation of the cellulose in the new cotton or new cellulose mixture: flax, hemp and/or cotton equal, accordingly, to 1800 and 3100; extrapolation of the level of decomposition of the cellulose (%) on graphics representing an age equivalent of the material depending on the level of decomposition of the cellulose using various graphics for the cotton and for said cellulose mixture.
Known in the art is a method for determining the dating of creation of handwritten texts and other written materials (RU, 2296315, C1), wherein two samples of the written material being tested are obtained. One of them is extracted by a solvent and the other sample at first is heated and is then extracted under the same conditions by the same solvent. The extraction results quantitative comparison is made, before the quantitative comparison of both samples are subjected to spectrophotometric analysis in which there is obtained a relation of the optical densities in the field of maximum of peaks of the colouring agents per unit length a dash sample of each sample calculating the ratio of the optical densities in the field from 400 to 1100 nanometers. The time dating of the studied document is determined by comparing these values with the similar parameters of this documents with a certainly known date of their creation, presented in a graphical or a tabular form.
Also are known in the art the methods for determining the age of elements of images applied onto a carrier surface wherein the age of the whole document is defined.
Known in the art is a method for determining the age of ink applied on a working surface with respect to other signatures or symbols by a change of the pH factor of the chemical compounds in the ink changing the composition in process of chemical reactions therein and corresponding to the age of the ink (U.S. Pat. No. 5,600,443, A).
Known in the art is a method for determining the age of hand-written fragments and texts made by a jet printing device, printing seals and the stamps made by stamping inks using the method of gas chromatography-mass spectrometry (Aginsky V. N. «Dating and Characterizing Writing, Stamp Pad and Jet Printer Inks by Gas Chromatography/Mass Spectrometry», International Journal of Forensic Document Examiners, Vol. 2, No. 3, July/September 1996, p. 103-116). This method is based on the dependence between the age of dash samples and the content of high-boiling organic solvents in the dash samples. The study includes the solvent extraction from the tested dash sample at first with a “weak” extragent, and then with a “strong” extragent, and determination of the solvent extraction level from the dash sample which decreases with the dash sample age. Then the accelerated (artificial) aging of the tested dash samples is performed (heating to 70° C. within 4 hours) and determination of the solvent extraction level is carried out as described above. In this method the main estimation criterion of the dash sample age is the difference in the characteristics of the solvent extraction level obtained before and after the artificial aging. The determination of the difference of the level of the solvent extraction is based on the quantitative analysis of the solvent extracted from the tested dash samples by the method of gas chromatography-mass spectrometry using the internal standard. However, the method does not takes into account the effect of the following factors: the compositions of the main components of the colorant in the studied dash samples, the character of its allocation in the compared dash samples, the completeness of the dash sample surface with extragents in the course of extraction, the nature of the “strong extragent”, the error of internal standard method when determining the amount of the solvent in the dash samples. Moreover, an insignificant dash sample colorant content can be determined mainly by the “background” content of solvent due to its migration from the dash sample to the other requisites.
Known in the art is a method for determination of the remoteness of the requisites in documents by relative: content of volatile solvents in their dash samples (RU, 2399042, C1), used in technical examination of documents for determining the authenticity and age of different types of documents whose requisites were made by a paste of ball pens, ink for gel pens, a jet printing method, and stamping inks. A microscopic technique is used for determining the sort of letter material in the dash samples and the fitness of the document requisites for a further study. At least two objects of study are obtained in the form of samples for analysis, one of them comprises the dash samples of the document requisites, and the other one is a piece of paper of the document free of dash. Each sample for analysis is subjected to thermal desorptions in a continuous gas flow for a certain time and at a given temperature with formation of a mixture of a carrier gas and thermal desorption products, then thermal desorption products are separated into some substances. The results of the analysis of the samples of a dash and/or paper are obtained in the graphical form of a curve, the presence and the amount of specific solvents in the dash sample are determined by the retention time and height of the peaks on the curve, the presence of thermal desorption products in the dash samples is determined in the paper products with the same retention time, as the retention time of the solvents in the examined dash samples, by the curve. The height of an appropriate peak on the curve—the dash sample chromatogram expressed in standard units taking into account the contribution of thermal desorption products from the paper being tested—is taken for the characteristic of the content of solvent in the dash sample. Then the colorant is extracted from the dash samples and the extracts obtained are subjected to a spectrophotometric analysis in the visible range of spectrum for determining the colouring agent content in the sample in the form of the obtained extract absorption spectrum curve in a spectrophotometer. However, in said method the sample of paper is used for exclusion effect of the paper thermal desorption products on the result of study of the solvents in the dash sample thermal desorption products, and this method is technologically very complicated, because it requires a significant amount of the reference data concerning the compounds consisted in a paper and a significant amount of the dash material in initial state and in the process of their age changing.
However, determination of the remoteness of an event of creation of documents as a whole man-made object by the dash age change applied thereon is not authentic since in the same document the dashes can be applied at various times in different fields of the document, for example, in case of local forgery. Besides, the study of the dash material compositions is a challenge because the change of the composition of these materials depends mainly on the conditions of plotting the dash on the document and on the conditions of subsequent state of the documents: temperature conditions of the document storage, radiation effects, steam effect and other factors.
As it is well known to specialists in the field of technical examination, at the present time the most informative parameters of the change of cellulose properties are:                a degree of crystallinity of the cellulose;        an average density of the amorphous regions;        a density of distribution of protons (amount of protons) in the studied sample with respect to which various methods of their determination are developed.        
It is also known that cellulose is a natural biopolymer consisting of crystalline and amorphous regions. In the course of physical and chemical effects, the volume and amount of the crystalline regions decrease and, as a consequence, the volume and amount of the amorphous regions increases that effects on the cellulose crystallinity degree and the cellulose molecular structure state characterized by the presence and density of proton distribution.
Thus, from the study of the cellulose structure by means of impulse NRM spectroscopy there is obtained a multistage NMR-relaxational function consisting of two components: a short high-relaxation component and long slow-relaxation component. It is well known that the cellulose structural characteristics are determined mainly by the short component of the relaxational function which carries information on the volume-mass ratio of the crystalline and amorphous phases of the polymer that allows one to determine not only the crystallinity degree but also to evaluate the average size of the crystalline and amorphous regions and their volumetric density.
It is also known that spin-spin relaxation time sensitively reacts to changes in the molecular system in the elementary links of the cellulose molecule: this amplitude of free induction signals (from here on referred to as the FIS) and the values of time of the spin-spin and spin-lattice relaxation allow one to obtain information on the state and properties of the cellulose when making the cellulose-containing material and when creating a man-made object having the cellulose-containing material and on their change as a result of various physical and chemical effects during the life of the cellulose-containing material.
Known in the art is a method for determining the degree crystallinity of cellulose (SU 1749800), in which a tested sample is wetted at a certain air humidity during certain time, excited and registered, for example, by means of nuclear-magnetic resonance spectroscopy, signals of the free induction (FIS) protons of the tested sample and the water reference, determine the amplitude of the standard signal As and the amplitude of the slowly relaxing component AOD of the sample signal, and the degree of crystallinity is determined from the relation
      K    =                                                      m              o                        ·                          A              ∋                                                          m              ∋                        ·                          A              OD                                      -        1                                                        m              o                        ·                          A              ∋                                                          m              ∋                        ·                          A              OD                                      -        1        +                  ρ          K                      ,where mO is the sample mass, g; m is the mass of an aqueous standard, g; ρK is the density in crystalline regions of the cellulose sample, g/cm3.
Known in the art is a method for determining the degree of crystallinity of natural polymers (RU 2175765, C1) including excitation and recording of the characteristic signal of the tested sample, in which the tested samples are wetted from 0 to hygroscopicity with a humidity from theoretically dry state to the hygroscopic state, and the characteristic signal is registered by means of the impulse nuclear-magnetic resonance spectrometer (NMR H1) of the free induction signal (FIS) of the drop of protons, then the FIS signal is used for determining the times of the spin-spin relaxation T2k of the short component, the humidity dependencies T2k are used for determining the characteristic times T20, T21, T22, T23 and the degree of crystallinity K by the formula:
      K    =          1      -                                    (                                          T                21                            -                              T                20                                      )                    +                      (                                          T                23                            -                              T                22                                      )                                    T          20                      ,
where T20 is the time of the spin-spin relaxation of the short component of theoretically dry sample;
T21 is the time of the spin-spin relaxation of the short component at the end of adsorption of the water molecules directly on the active centres in the amorphous regions of the polymer sample:
T22 is the time of spin-spin relaxation of the short component at filling the monomolecular layer of the water molecules;
T23 is the time of the spin-spin relaxation of the short component at a hygroscopic water content of the sample.
Known in the art is a method for determining proton-containing substances in the initial, intermediate and finished cellulose-based products (RU, 2053503, C1), in which the free induction signal (FIS) of protons is registered as a characteristic signal, the tested and reference samples of same mass are placed one after another in a sensor for establishing the nuclear magnetic resonance, the samples are attacked by impulses, the amplitude of the short FIS component is recorded from the initial and processed samples. After that there are determined the amplitudes AIK and AEK of the short components of the signals, accordingly, for the tested and reference samples, and the crystallinity degree K is calculated using the formula:K=1−(AK·m/AK·m),where AH and A are the amplitudes of the short component FIS of the tested and reference samples. respectively; m and m are respectively the masses of the reference and tested samples which beforehand were dried up to a constant mass.
However the estimation of the cellulose age by one parameter only is not completely justified because in one sample of an object or an article the areas of a cellulose-containing material of various compositions can be available, in a different degree of the environmental effect, for example, in connection with the presence thereon of protecting coatings, for example, color agents, ink, varnishes. Besides, the time of a coating application on various areas of the object may be different and not corresponding to the initial creation time of the document, and due to the mutual effect of their coating and the substrate determination of the age of a substrate made of a cellulose-containing material including different types of cellulose and different by the composition on the basis of study of one index is insufficient, and using of several methods of testing associated with sampling by distractive methods leads to damage of the document or article. Thus in the described method taking the samples leads to violation of integrity of the tested article.
Therefore, so far there are no methods of determination and criteria of a simultaneous total estimation of parameters of the cellulose state in a cellulose-containing material on different areas of an object, both unprotected and protected in a different level of environmental effects, thereby stipulating the age and time of the event of coating application thereon, without a labour-consuming estimation of changes of the physical and chemical properties of the applied coatings and without violation of the article integrity.
Therefore, the problem of creation of a method for determination of the remoteness of an event of creation of a man-made object made of a cellulose-containing material or a man-made object fragment made of a cellulose-containing material having different elements of coatings, and a method for determination the remoteness of the event of such coating application on the surface of the cellulose-containing material is very actual.
Besides, the problem of determination of the remoteness of event of creation of a man-made object is intimately connected to the problem of protection of a man-made object from falsification of the remoteness of its creation because the existing methods of counterfeit detection are basically connected with taking off a large enough sample of the man-made object material that leads to violation of its integrity, and also associated with a labour-intensive process of studying the properties of the material and coating in their aging and changing under the environmental effects.